This is a poor design to start with. The problem area could be constructed to eliminate the dead valley.
I have never seen a roof damaged by raccoons other than wood shingles or shakes, and even those have to be old and degraded. GAF warranty is garbage and anyone who blames animals for valley damage, other than piles of rancid fesces, is a scam artist.
I have noticed many with the “opinion” that ice and water shield isn’t needed here or there. I would point out…ITS REQUIRED for warranty in many areas by the manufacturers. ALL valleys…not just the ones we think need it. Velux sends their own with the flashing kit.
Some of us are from a time before Ice & water shield existed and know how to install a leak free roof without it.
It’s not our place to make those choices. If it’s “required” for warranty and you choose not to follow those “minimal” standards then you aren’t a roofing “contractor”…just another guy with a hammer and a truck. We don’t pretend to know more than the companies that spend millions in r&d trying to improve their products or to give the customer better security. There was a time we didn’t travel in combustion driven forms of transportation…how many people go to work via horseback?
So you’re a 30 yr guru who can’t install a non leaking roof without ice & water shield?
Ice & water shield is only effective if non-corrosive nails are used and electro-galvanised nails are not non-corrosive.
Do you spend 5x as much for non-corrosive roofing nails, some do.
Of course we can. It still isn’t my place or any other contractors to skip necessary steps or materials that could compromise the owners “full” warranty from the manufacturers. That dog don’t hunt ax. I know you are a confident, knowledgeable roofer…but if you truly believe you are right rather than just belaboring a point…then you are wrong still. The ice and water is “required”…not “if you think you need it…put it there.”
The problem with experience is it often stands in the way of progress and new ways of thinking or doing things. Thus the conversation taking place in this forum. Op points out specs in contract. Roofer failed. End of topic.